The present invention relates to a hoisting device in particular a block having provisions for raising a load and for lowering a load with a braking function, so that the descent of the load can be controlled with relatively small force.
In my application, Ser. No. 927,364 now U.S. Pat. No. 4,264,056 there is disclosed a block comprising a case having a two spaced sides and a top portion connecting the sides and provided with means for suspending the block from a support. A rotatable sheave is rotatably supported in the case by a fixed shaft which extends between the sides of the case and projects outwardly of one of the sides. A braking sheave is fixed non-rotatably on the projecting portion of the shaft. For a hoisting operation, a rope is passed over the rotatable sheave so that a force applied on one end of the rope will hoist a load suspended on the other end. For lowering operation, the rope passes through a notch at the lower side of the case and up over the fixed braking sheave, thereby making it possible to exert a snubbing effect on the rope. A cover of elastomeric material on the outer face of the fixed sheave has a rim which is directed in towards the case so as to assure the holding fast of the rope on the fixed sheave.